Vortex Flow Developed in the Vicinity of a Wall of an Elastic Heaving Airfoils and its Wake Structure

Abstract

The authors have previously extensively investigated the flow field around an unsteady airfoil both experimentally and a numerically. In particular, we have performed a number of studies on wake structures and have reported the characteristics of dynamic thrust of an unsteady airfoil. However, the behaviors of vortices that form wake structures and processes from generation to development have not yet been clarified. The authors measured the flow field in the vicinity of a wall including the boundary layers by particle image velocimetry measurements and clarified the growth and development of vortices generated in the vicinity of the wall and the process of wake structure formation quantitatively. We clarified that the vortex flow in the vicinity of the wall and the process of wake structure formation are different between the rigid NACA0010 and the elastic NACA0010, whereas the wake structures for which flow fields are averaged for one heaving cycle become almost the same in the wake of the rigid NACA0010 and the elastic NACA0010.

Keywords

• vortex
• elastic airfoil
• vicinity of a wall
• wake structure